Official papers confirm low-income families will be worse off under the National Government's tax cut package, compared with Labour's.
Radio New Zealand's political editor says papers obtained under the Official Information Act, also show that higher earners will be better off.
From April 2011, a person with children earning $40,000 a year will pay $250 more a year in tax than if Labour had stayed in power. The less money earned, the bigger the loss.
However, someone earning $100,000 will be $750 a year better off than under Labour.
Low-income single workers who do not get Working for Families tax credits will also be much better off.
A single person earning $40,000 will get an extra $530 a year by 2011 under the Government's package.